How to Use Sonda Sensor TDS: Examples, Pinouts, and Specs

The Sonda Sensor TDS (Total Dissolved Solids) is an electronic device designed to measure the concentration of dissolved solids in a liquid. TDS is typically expressed in parts per million (ppm) and is indicative of water quality. This sensor is widely used in applications such as water purification systems, environmental monitoring, aquariums, and hydroponics to ensure the water is suitable for its intended use.

• Water quality testing for drinking water
• Monitoring and controlling TDS levels in aquariums
• Hydroponic nutrient level measurement
• Industrial water processing
• Environmental water analysis

• Measurement Range: 0-9990 ppm
• Accuracy: ±2% F.S.
• Operating Voltage: 3.3V to 5.5V
• Output Voltage: 0-2.3V (corresponding to 0-4.7V input)
• Response Time: <1s
• Operating Temperature: 0-50°C

1. Connect the VCC pin to a 3.3V or 5V power supply.
2. Connect the GND pin to the ground of the power supply.
3. Connect the AOUT pin to an analog input on your microcontroller (e.g., Arduino UNO).

• Ensure the sensor is properly calibrated before use.
• Avoid touching the sensor electrodes to prevent contamination and inaccurate readings.
• The sensor should be submerged in the liquid with the electrodes fully immersed.
• Regularly clean the sensor to maintain accuracy.
• Use a pull-down resistor if necessary to stabilize the output signal.

// Define the TDS sensor's output pin
const int TdsSensorPin = A0;

void setup() {
  // Initialize serial communication at 9600 baud rate
  Serial.begin(9600);
}

void loop() {
  // Read the analog value from sensor
  int analogValue = analogRead(TdsSensorPin);
  
  // Convert the analog value to TDS value
  float voltage = analogValue * 5.0 / 1024.0;
  float tdsValue = (133.42 * voltage * voltage * voltage - 255.86 * voltage * voltage + 857.39 * voltage) * 0.5;
  
  // Print the TDS value to the serial monitor
  Serial.print("TDS Value: ");
  Serial.print(tdsValue);
  Serial.println(" ppm");
  
  // Wait for a second before taking the next reading
  delay(1000);
}

• TdsSensorPin: Analog pin to which the sensor is connected.
• analogRead(TdsSensorPin): Reads the analog value from the sensor.
• voltage: Converts the analog value to voltage.
• tdsValue: Calculates the TDS value based on the voltage.
• Serial.print: Outputs the TDS value to the serial monitor.
• delay(1000): Pauses the loop for one second between readings.

• Inaccurate Readings: Ensure the sensor is calibrated correctly and that the electrodes are clean.
• No Readings: Check the connections to the Arduino and ensure the sensor is powered.
• Fluctuating Readings: Stabilize the sensor in the liquid and use a pull-down resistor if necessary.

• Calibration: Follow the manufacturer's instructions to calibrate the sensor using a standard solution.
• Cleaning: Gently clean the sensor electrodes with distilled water and a soft brush.
• Stabilization: Secure the sensor in the liquid to prevent movement that could affect readings.

• Q: Can the sensor be used in saltwater?

  • A: Yes, but ensure it is within the sensor's measurement range and is calibrated for saltwater.

• Q: How often should the sensor be calibrated?

  • A: Calibration frequency depends on usage, but typically once every month or after any maintenance.

• Q: Is it necessary to use a pull-down resistor?

  • A: It may be necessary if you observe fluctuating readings due to a floating analog input. A 10kΩ resistor from AOUT to GND can help stabilize the readings.